A stenosed blood vessel can be life threatening and often requires therapeutic intervention. Nonsurgical intervention procedures have been used with increasing regularity in recent years as a treatment for stenosed arteries. Examples of nonsurgical intervention include treatments such as balloon angioplasty, mechanical removal, laser fiber-optical treatment and localized chemical treatment.
These procedures typically involve the percutaneous introduction of the treatment device into the lumen of the artery, via a catheter. For example, balloon angioplasty involves the use of a special catheter having a balloon at its distal end. The catheter is inserted percutaneously into the patient's arterial system and is advanced and manipulated to place the balloon within the stenosis in the artery. The balloon then is inflated under substantial pressure to press the plaque and plaque-laden arterial wall radially outwardly to enlarge the stenosed region of the artery. When successful, the procedure may avoid the necessity for major surgery.
Treating cerebral arteries poses unusual risks The above listed forms of non-surgical treatment potentially involve the release of debris into the circulation as the plaque is manipulated by balloon angioplasty, mechanical removal laser, fiber optical treatment and localized chemical treatment. The debris can then be carried distally by the circulating blood to the vessels of the brain where they can occlude cerebral vessels resulting in a stroke, having potentially devastating effects. Although cerebral percutaneous transluminal angioplasty has been clinically performed, previous experience has been limited to a small number of dilitations of proximal, extra-cranial vessels, and rare cases of distal intra cranial vessels with commercially available dilatation balloons. Fear of causing embolic strokes has thus far prevented the wide spread use of balloon angioplasty in the cerebral vascular system.